Question

Which of the following statements are the functions of a medullary ray in plants?
(i) Storage of food
(ii) Secondary growth
(iii) Transmission of water
(iv) Place of origin of interfascicular cambium
A. i, ii, and iii
B. i, iii, and iv
C. ii, iii, and iv
D. All of the above are correct

Answer 1

Hint: Medullary rays are cellular structures found in certain wood species. They are visible to the naked eye as radial planar structures are perpendicular to the growth rings. They appear as radiating lines from the center of the log in a transverse section.

Complete answer:
Medullary rays can appear as a variety of transverse markings in an axial section, depending on how close the section is to the ray's plane. They may be difficult to see in a tangential section.
They are formed as a result of the activity of the fascicular cambium. During the process of cambium division, the cambium cuts out cells from both the outer and inner sides. These are parenchymatous cells. The majority of these cells differentiate into xylem and phloem. Certain cells, however, do not transform into xylem and phloem and remain so.
Medullary rays are vertical plates of parenchyma cells that run parallel through the vascular tissue cylinder. Radial conduction of water, minerals, and other organic substances are one of its functions.
Food preservation.
Tannin and crystal deposition
Gas exchange occurs in the intercellular spaces.
It aids in secondary growth.
Origin of the interfascicular cambium.

So the correct option is Option D: 'All of the above are correct’.

Note:
Rays can be seen running perpendicular to the growth rings in wood products. When wood is cut into boards with the growth rings roughly perpendicular to the board's face, the medullary rays frequently produce beautiful "figures" such as silver grain, medullary spots, pith flecks, and so on.